There are a number of medical conditions for which systemic cooling is an effective therapy. For example, rapid systemic cooling of stroke, head-trauma, cardiac arrest, and myocardial infarction patients has significant therapeutic benefits.
In that regard, stroke is a major cause of neurological disability, but research has established that even though a stroke victim's brain cells may lose their ability to function during the stroke, they do not necessarily die quickly. Brain damage resulting from a stroke may take hours to reach a maximum level. Neurological damage may be limited and the stroke victim's outcome improved if a cooling neuroprotectant therapy is applied during that timeframe.
Similar possibilities exist with victims of trauma, such as may result from vehicle crashes, falls, and the like. Such trauma may impart brain injury through mechanisms that have overlap with elements in the genesis of neurologic damage in stroke victims. Delayed secondary injury at the cellular level after the initial head trauma event is recognized as a major contributing factor to the ultimate tissue loss that occurs after brain injury.
Further, corresponding possibilities exist with cardiac arrest and myocardial infarction patients. Again, rapid cooling of such patients may limit neurological damage. In addition, rapid cooling may provide cardio protection. Further in that regard, rapid heart cooling of myocardial arrest patients prior to reperfusion procedures (e.g., carotid stenting) may significantly reduce reperfusion-related injuries.
Additionally, patients having a neurological disease may often have accompanying fever. Cooling such patients has been recently proposed to yield therapeutic benefits, but may entail cooling over an extended period of time.
Various approaches have been developed for applying cooling therapy. In one non-invasive approach, a contact pad may be placed on a patient's torso and a cooled fluid, such as cooled water or air, circulated through the pad. Thermal energy is then exchanged between the patient and the circulated fluid to cool the patient. Other proposed approaches provide for esophageal cooling or invasive, intravascular cooling of a patient.